From: Pavel Butsykin <pbutsy...@virtuozzo.com> >From time to time qemu-nbd is crashing on the following assert: assert(state == TERMINATING); nbd_export_closed nbd_export_put main and the state at the moment of the crash is evaluated to TERMINATE.
During shutdown process of the client the nbd_client_thread thread sends SIGTERM signal and the main thread calls the nbd_client_closed callback. If the SIGTERM callback will be executed after change the state to TERMINATING, then the state will once again be TERMINATE. To solve the issue, we must change the state to TERMINATE only if the state is RUNNING. In the other case we are shutting down already. Signed-off-by: Pavel Butsykin <pbutsy...@virtuozzo.com> Signed-off-by: Denis V. Lunev <d...@openvz.org> CC: Paolo Bonzini <pbonz...@redhat.com> Message-id: 1460629215-11567-1-git-send-email-...@openvz.org Signed-off-by: Max Reitz <mre...@redhat.com> --- qemu-nbd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/qemu-nbd.c b/qemu-nbd.c index b5751f8..2c9754e 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -215,7 +215,7 @@ static int find_partition(BlockBackend *blk, int partition, static void termsig_handler(int signum) { - state = TERMINATE; + atomic_cmpxchg(&state, RUNNING, TERMINATE); qemu_notify_event(); } -- 1.8.3.1